Localization of sub

I have a Sunfire true subwoofer 1 which was updated last year but you hear the sound coming from that corner of the room. It sits in the left rear corner of the room and unfortunately is the only placement. It has a 40ft cable which links to a Marantz 19. Is there a way to compensate or trick the subwoofer with the distance setting on the receiver or is the that one of the problems with the setup I have or with Sunfire subs? Any suggestions or thoughts would be appreciated. I'd hate to get rid of the sub without exhausting the solutions.

Thanks Brian
Couple of things that might cause you to hear it.

It is crossed over too high.
It is turned up too loud.
It or something in the corner is resonating.

Or more likely a combination of some of those things and the fact that it is behind you. I think the only hope you have is to have a low crossover frequency and turn it down.
I agree with Herman and have the drivers facing each side of the wall in corner.
Thank you for your suggestions. I'll try turning the cross lower and pulling it out from the corner a little as much as I can.

How is the feedback on the True sub?